Information reproducing apparatus, method of correcting reproducing program, and information recording medium

ABSTRACT

An information reproducing apparatus, in which a disk having correction data recorded thereon is placed, acquires region information indicative of a region corresponding to the correction data after load processing is performed by a ROM loader. Then, under the control of a CPU, the apparatus determines the correction data to be used for correcting a reproducing program based on the region information, reads the correction data from a lead out area or its outer region on the disk, temporarily retains the read correction data in a first RAM or a second RAM, and then stores the correction data to be resident in a nonvolatile first flash memory or a second flash memory, to correct the reproducing program based on the correction data. The information reproducing apparatus thereafter reproduces user data recorded on the disk according to the corrected reproducing program.

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] The present invention relates generally to an informationrecording medium such as an optical disk on which various contentobjects are already recorded and an information reproducing apparatusthat reproduces such content objects from the information recordingmedium. More particularly, the invention is directed to a method ofcorrecting a reproducing program executed by the information reproducingapparatus using correction data recorded on the information recordingmedium.

[0003] 2. Description of Related Art

[0004] Prior-art optical disk players that play an optical disk such asa DVD on which various content objects are already recorded sometimesencounter, after shipped from factories, trouble caused by bugs in theirplaying program. A user facing such trouble when trying to play a DVD onhis or her optical disk player contacts the maker of the optical diskplayer to have the player troubleshooted so that the maker will takeeffective measures to fix the trouble. It usually takes a considerabletime before the optical disk player is fixed, to both the user's andmaker's disadvantage, probably more to the maker's disadvantage in thatthe maker has to accommodate similar complaints from many users spendingits time and money. In addition, trouble likely to be encountered bythese optical disk players tends to become increasingly complicated dueto differences in content data, incompatibility among variousspecifications and standards, and problems associated with authoringtools, etc., to such an extent that a drastic measure seems difficult.

[0005] Under such circumstances, JP-A-7-85638 proposes one solution toeliminate trouble such as mentioned above. In this solution, patch datafor the playing program is produced, then an optical disk isdistributed, on which the generated patch data is recorded in itspredetermined area so that an optical disk player reads the recordedpatch data to correct its playing program. This solution permits theoptical disk player to automatically correct its playing program uponplacing of the optical disk in the optical disk player.

[0006] However, in view of the fact that such trouble is often causeddue to optical disk players being available in a diversity of models, itis necessary to prepare a plurality of types of correction datacompatible with different models of optical disk players. Therefore, itis desirable that the plurality of types of correction data are recordedon an optical disk. To record the plurality of types of correction dataon an optical disk, a sizable area needs to be reserved on the opticaldisk. However, the data size usable in a lead-in area is so limited thatit is difficult to record the plurality of types of correction data tosuch an extent as to take care of trouble associated with a diversity ofplaying programs.

SUMMARY OF THE INVENTION

[0007] The invention has been made to satisfy the above need. It is,therefore, an object of the invention to provide an informationreproducing apparatus, a method of correcting a reproducing program, andan information recording medium which upon occurrence of trouble in thereproducing program, are capable of correcting the reproducing programquickly and properly based on a plurality of types of correction datacorresponding to different reproducing programs which are dependent upondifferent models, etc. of information reproducing apparatuses.

[0008] The above object of the present invention can be achieved by aninformation reproducing apparatus of the present invention that correctsa reproducing program using correction data recorded on an informationrecording medium to reproduce record information recorded on theinformation recording medium. The apparatus is provided with: acorrection control device for reading the correction data to be used tocorrect the reproducing program, from the information recording mediumon which the correction data is recorded in a lead out area, to correctthe reproducing program based on the read correction data; and areproduction control device for reproducing the record informationrecorded on the information recording medium according to a latestversion of the reproducing program which is corrected by the correctioncontrol device.

[0009] According to this invention, if the information reproducingapparatus encounters trouble associated with the reproducing programwhen reproducing the record information recorded on the informationrecording medium, the information reproducing apparatus reads thecorrection data from the lead out area of the information recordingmedium to correct the reproducing program using the read correctiondata, so that the information reproducing apparatus can thereafterreproduce the information recording medium using the latest version ofthe reproducing program. Thus, for trouble associated with thereproducing program to be executed by the information reproducingapparatus, the maker of the information reproducing apparatus no longerneeds to recall its product to reduce its cost and time that wouldotherwise be incurred for fixing the trouble. The user can also stopworrying about correction to his or her advantage. In addition, thecorrection data is recorded in the lead out area in which a larger sizecan be reserved therefor than in the lead in area where various controlinformation is usually recorded, so that various types of correctiondata can be used to properly correct different reproducing programsdependent upon different information reproducing apparatuses.

[0010] The above object of the present invention can be achieved by aninformation reproducing apparatus of the present invention that correctsa reproducing program using correction data recorded on an informationrecording medium to reproduce record information recorded on theinformation recording medium. The apparatus is provided with: acorrection control device for reading the correction data to be used tocorrect the reproducing program, from the information recording mediumon which the correction data is recorded in an area radially outward ofa lead out area, to correct the reproducing program based on the readcorrection data; and a reproduction control device for reproducing therecord information recorded on the information recording mediumaccording to a latest version of the reproducing program which iscorrected by the correction control device.

[0011] According to this invention, the reproducing program can becorrected using the correction data recorded in an area radially outwardof the lead out area, in a similar configuration to the above invention.Thus, various types of correction data can be used to properly correctdifferent reproducing programs dependent upon different informationreproducing apparatuses in accordance with operations and advantagescommon to the above invention.

[0012] In one aspect of the present invention, the informationreproducing apparatus is further provided with a nonvolatile storagedevice for storing the correction data, wherein the correction controldevice records the correction data in a predetermined location of thestorage device, and the reproduction control device executes a correctedversion of the reproducing program after confirmation that thecorrection data is recorded normally.

[0013] According to this aspect, upon locating the correction data onthe information recording medium, the information reproducing apparatusrecords the correction data at a predetermined position of thenonvolatile storage device, and executes the corrected version of thereproducing program after confirmation that the correction data isnormally recorded. Thus, once the reproducing program is corrected basedon the correction data, the information reproducing apparatus allows thecorrected version of the reproducing program to reside in thenonvolatile storage device, and hence the information reproducingapparatus can automatically execute the corrected version of thereproducing program thereafter without involving any complicatedcontrol.

[0014] In another aspect of the present invention, the correctioncontrol device records a start position of the correction data as astart position address, and the reproduction control device executes thecorrected version of the reproducing program by searching the startposition address.

[0015] According to this aspect, when recording the correction data inthe nonvolatile storage device, the information reproducing apparatusrecords a start position address corresponding to the head of thecorrection data, to use the recorded start position address forexecution of the corrected version of the reproducing program. Thus, theposition where the correction data is recorded can be accuratelylocated, to allow the reproducing program to be executed reliably.

[0016] In further aspect of the present invention, while the correctiondata is recorded in the storage device, an operation of turning offpower is prohibited.

[0017] According to this aspect, the information reproducing apparatusis prohibited from being turned off during the recording of the locatedcorrection data in the nonvolatile storage device. This arrangement thusprevents destruction of the corresponding type of correction data due toinadvertent turning off of the power of the information reproducingapparatus.

[0018] In further aspect of the present invention, the correction datais provided with difference data between an original version of thereproducing program and a corrected version of the reproducing program,and the correction control device corrects the reproducing program basedon the original version of the reproducing program and the differencedata.

[0019] According to this aspect, once the information reproducingapparatus locates the correction data on the information recordingmedium, a corrected version of the reproducing program can be obtainedfrom the correction data given as difference data and the originalversion of the reproducing program. Thus, the size of the correctiondata can be reduced, to leave the size of user data unreduced.

[0020] The above object of the present invention can be achieved by amethod of the present invention of correcting a reproducing programusing correction data recorded on an information recording medium. Themethod is provided with: the process of reading the correction data tobe used to correct the reproducing program, from the informationrecording medium on which the correction data is recorded in a lead outarea; and the process of correcting the reproducing program based on theread correction data.

[0021] According to this aspect, the reproducing program requiringmeasures to eliminate trouble can be corrected based on the correctiondata, by similar operations to the above invention. Thus, various typesof correction data can be used to properly correct different reproducingprograms dependent upon different information reproducing apparatuses.

[0022] The above object of the present invention can be achieved by amethod of the present invention of correcting a reproducing programusing correction data recorded on an information recording medium. Themethod is provided with: the process of reading correction data to beused to correct the reproducing program, from the information recordingmedium on which the correction data is recorded in an area radiallyoutward of a lead out area; and the process of correcting thereproducing program based on the read correction data.

[0023] According to this invention, the reproducing program requiringmeasures to eliminate trouble can be corrected based on the correctiondata, by similar operations to the above invention. Thus, various typesof correction data can be used to property correct different reproducingprograms dependent upon different information reproducing apparatuses.

[0024] In one aspect of the present invention, the method is providedwith: the process of recording the correction data at a predeterminedposition of a nonvolatile storage device; and the process of recording astart position of the correction data as a start position address.

[0025] According to this aspect, the correction data is allowed toreside in the nonvolatile storage device for subsequent effective usewithout involving any complicated control, by similar operations to theabove invention.

[0026] In another aspect of the present invention, the correction datais provided with difference data between an original version of thereproducing program and a corrected version of the reproducing program,and the reproducing program is corrected based on the original versionof the reproducing program and the difference data.

[0027] According to this aspect, the size of the correction data as thedifference data can be reduced, by similar operations to the aboveinvention.

[0028] The above object of the present invention can be achieved by aninformation recording medium of the present invention on which recordedinformation as well as correction data for correcting a reproducingprogram executed by an information reproducing apparatus are recorded,wherein the correction data is recorded in a lead out area.

[0029] According to this invention, the correction data are recorded inthe lead out area of the information recording medium to correct thereproducing program by using the correction data as mentioned above.Thus, different reproducing programs can be corrected as the informationrecording medium encounters such different reproducing programs when puton a general distribution channel, to both the user's and maker'sadvantage.

[0030] The above object of the present invention can be achieved by aninformation recording medium on which recorded information as well ascorrection data for correcting a reproducing program executed by aninformation reproducing apparatus are recorded, wherein the correctiondata is recorded in an area radially outward of a lead out area.

[0031] According to this invention, the correction data are recorded inan area radially outward of the lead out area of the informationrecording medium to correct the reproducing program by using thecorrection data as mentioned above. Thus, different reproducing programscan be corrected as the information recording medium encounters suchdifferent reproducing programs when put on a general distributionchannel, to both the user's and maker's advantage.

[0032] In one aspect of the present invention, the correction data isrecorded in a recording format different from a recording format inwhich the recorded information is recorded.

[0033] According to this aspect, the user data and the correction dataare recorded on the information recording medium in different dataformats, respectively. This arrangement thus prevents any third partyfrom abusing the correction data by making it hard to analyze thecorrection data or by encrypting the correction data, for example.

[0034] In another aspect of the present invention, the correction dataeach comprises difference data between an original version of thereproducing program and a corrected version of the reproducing program.

[0035] According to this invention, the correction data are recorded inthe form of difference data which is small in size, by similaroperations to the above invention. Thus, an information recording mediumhaving an unreduced user data storage area can be provided.

BRIEF DESCRIPTION OF THE DRAWINGS

[0036]FIG. 1 is a block diagram showing major parts of an optical diskplayer as an information reproducing apparatus to which the invention isapplied;

[0037]FIG. 2 is a diagram schematically showing the data structure of adisk placed in the optical disk player;

[0038]FIG. 3 is a first flowchart showing a process of correcting aplaying program, performed by the optical disk player;

[0039]FIG. 4 is a second flowchart showing the process of correcting theplaying program, performed by the optical disk player;

[0040]FIG. 5 is a diagram showing the structure of a correction datatable read in step S22 of FIG. 4; and

[0041]FIG. 6 is a diagram showing the sector format of a DVD.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

[0042] A preferred embodiment of the invention will now be describedwith reference to the drawings. The preferred embodiment refers to thecase where the invention is applied to an optical disk player as aninformation reproducing apparatus that plays an information recordingmedium on which data are already recorded.

[0043] Referring to FIG. 1, the optical disk player, in which a ROM disk10 as a read-only information recording medium is placed to play userdata corresponding to content, is generally provided with a pickup 11, adata demodulator 12, an MPEG demodulator 13, an NTSC video modulator 14,a CPU 15, a ROM loader 16, a first RAM 17, a second RAM 18, a firstflash memory 19, and a second flash memory 20.

[0044] Referring then to FIG. 2, the data structure of the disk 10placed in the optical disk player will be described. The disk 10 ismarketed with data already recorded thereon, the data being MPEG orsimilarly coded data corresponding to content such as, for example,films. As shown in FIG. 2, the disk 10 has three recording areas, i.e.,a lead-in area, a user data area, and a lead-out area laid out from theinner toward the outer side.

[0045] The lead-in area includes cryptographic information used toencrypt the content for copyright protection, and disk informationindicative of the physical characteristics of the disk 10. The user dataarea includes file system information indicative of the data structurefor recording the content by conversion into files, navigationinformation used to display menus and sequences necessary for playbackcontrol, and user data such as video/audio data corresponding to thebody of the content already recorded at the factory. The lead-out areadefines the end of the data recorded on the disk 10.

[0046] On the disk 10 according to this embodiment, the correction datanecessary for correcting a playing program in the optical disk player isalready recorded. Specifically, in order to take care of troubleassociated with the optical disk player in playing a specific contentobject, correction data are embedded in the disk 10 in a manner usableby the optical disk player. While the correction data may be embedded inany of the lead-in area, user data area, lead-out area and outer regionof the lead-out area, the following description refers to the case ofembedding the correction data in the lead-out area or its outer region.How the playing program is corrected using the correction data by theoptical disk player will be described below.

[0047] Referring back to FIG. 1, the pickup 11 irradiates a recordingtrack of the rotating disk 10 with an optical beam through optics, andalso receives reflected light from the information recorded surface ofthe disk 10 to output photoelectrically converted read signals.

[0048] The data demodulator 12 subjects the received read signals fromthe pickup 11 to signal processing including waveform shaping,demodulation, and analog-to-digital conversion, to output digitalsignals corresponding to the content. The demodulator 12 also outputsthe above-mentioned correction data, which is required to correct theplaying program as will be described below.

[0049] The MPEG demodulator 13 demodulates the digital signalsdemodulated by the data demodulator 12, in a manner compatible with anMPEG format to separately generate video and audio data outputscorresponding to the content. The video data output is fed to the NTSCvideo modulator 14 to generate an NTSC-compatible video output for anexternal device. The audio data, which is generated as stereophonic L/Rsignals, is also output to an external device.

[0050] The CPU 15 performs general control over the operations of theoptical disk player shown in FIG. 1. The CPU 15 is coupled to variousmemory means and the ROM loader 16 via a data bus. The memory meansusable by the CPU 15 are the first and second RAMs 17 and 18 fortemporarily retaining data, and the first and second flash memories 19and 20 as nonvolatile memories. The CPU 15 serves as a correctioncontrol device and a reproduction control device of the invention incooperation with other components.

[0051] The ROM loader 16 performs load processing under the control ofthe CPU 15 prior to playing the disk 10 loaded in the optical diskplayer. At the playing start, the ROM loader 16 loads, to the first orsecond RAM 17 or 18, the playing program to be finally stored in thefirst or second flash memory 19 or 20.

[0052] The first and second RAMs 17 and 18 are volatile memory devicesused by the CPU 15 for its control processing, and temporarily retainthe playing program, which needs to be loaded every time the opticaldisk player is turned on. In contrast, the first and second flashmemories 19 and 20 are nonvolatile memory devices used to make residenttherein the playing program temporarily retained in the first and secondRAMs. Thus, even when the optical disk player is tuned off or even whenthe data in the first and second RAMs 17 and 18 are deleted, the playingprogram can be retained in the first and second flash memories 19 and20.

[0053] It should be appreciated that a dual configuration comprising apair of RAM-flash memory systems is proposed in this embodiment in orderto implement correction of the playing program. Briefly, while thememory device in one of the pair of RAM-flash memory systems isexecuting the playing program, the memory device in the other systemstores a corrected version of the playing program, which is correctedusing the correction data recorded on the disk 10. This configurationwill be described in more detail below.

[0054] Referring next to FIGS. 3 and 4, a process of correcting theplaying program, performed by the optical disk player according to thisembodiment will be described. The process shown in FIG. 3 starts whenthe optical disk player is turned on. First, whether or not the disk 10is placed in the optical disk player is determined (step S11 ). If so(“YES” in step S11), the disk 10 is driven to rotate (step S12).

[0055] Then, a focus servo is activated (step S13). Upon confirmationthat the focus servo loop is closed to be locked (“YES” in step S14), atracking servo is then activated (step S15). Successively, uponconfirmation that the tracking servo loop is closed to be locked (“YES”in step S16), the rpm of the disk 10 is checked (step S17). If the rpmhas reached a predetermined value after a predetermined time has elapsed(“YES” in step S17), then the head of the disk information is searchedin order to read various information recorded in the lead in area of thedisk 10 (step S18).

[0056] If it is not confirmed that the focus servo is locked (“NO” instep S14), if it is not confirmed that the tracking servo is locked(“NO” in step S16), or the rpm has not reached the predetermined valueafter the predetermined time has elapsed (“NO” in step S17), the processof FIG. 3 proceeds to an abnormal end routine.

[0057] Referring next to FIG. 4, if it is determined that the disk 10has correction data based on information read in step S18 (“YES” in stepS19), then a disk ID as an identifier contained in the disk informationis read from the lead in area (step S20). Otherwise (“NO” in step S19),the process of FIG. 4 is brought to an end.

[0058] Successively, if it is determined that the playing program in theoptical disk player has never been corrected by a type of correctiondata corresponding to the disk 10 based on the disk ID read in step S20(“NO” in step S21), then the start address of a correction data tablelocated in a predetermined area of the disk 10 is searched to read thecorrection data table (step S22). If, on the other hand, the playingprogram has been corrected by the corresponding type of correction data(“YES” in step S21), then the process of FIG. 4 is brought to an end.

[0059] Referring here to FIG. 5, the correction data table contains, asinformation relevant to the type of correction data corresponding to thedisk 10 to be read in step S22, a company name, a product ID No., acorrection data version, a corresponding region, a correction data startaddress, and a correction data size. Thus, based on the correction datatable, information unique to the disk 10 and information relevant to thetype of correction data corresponding to the disk 10 can be identified.It should be noted that the correction data table contains as manycorrection data start addresses, correction data sizes, etc. as aplurality of types of correction data which are recorded to fix troubledependent upon different models, etc. of optical disk players.

[0060] In this embodiment, the company name, product ID No. andcorrection data version contained in the correction data table arecompared with the company name, product ID No. and playing programversion stored in the optical disk player to make a first determinationas to whether or not correction is necessary (step S23). If these itemsof information in the optical disk player do not match the equivalentson the disk 10 (“NO” in step S23) so that no correction is necessary,the process of FIG. 4 is terminated immediately. If the firstdetermination indicates that correction is necessary (“YES” in stepS23), then the “corresponding region” contained in the correction datatable of the disk 10 is compared with regional information about wherethe optical disk player is sold which is stored in the optical diskplayer to make a second determination as to whether or not correction isnecessary (step S24). Specifically, the “region” corresponding to thecorresponding type of correction data, not “region” corresponding to aspecific content object on the disk 10 itself, serves as the basis fordetermining necessity of correction in terms of “regional aspects” ofthe playing program to be corrected. The “corresponding region”corresponding to the corresponding type of correction data on the disk10 helps determine necessity of correction in order to eliminate troubleassociated with factors suggestive of region such as the model of aparticular maker and the language of a particular country, for example.This multi-stage determination configuration narrows the aspects of thetrouble to be fixed by correction down to the “region” specified by the“corresponding region” in order to obviate wasteful correction.

[0061] If the regional aspect of the optical disk player does not matchthe corresponding region through the second determination (“NO” in stepS24), then the process of FIG. 4 is immediately terminated. Otherwise(“YES” in step S24), various operations such as turning off the opticaldisk player and giving user commands are prohibited (step S25).Successively, the corresponding correction data is read from the leadout area or its outer region on the disk 10, and the read correctiondata is recorded in the second RAM 18 and the second flash memory 20(step S26). The prohibition of various operations in step S25 is toprevent abnormality from occurring during the reading and recording ofthe correction data in step S26.

[0062] In step S26, the correction data start address and correctiondata size contained in the correction data table are read, and the startaddress is then searched to read a predetermined size of thecorresponding type of correction data. Thereafter, the correspondingtype of correction data which has been read is developed in both thevolatile second RAM 18 and the nonvolatile second flash memory 20.

[0063] It is desirable here that the correction data according to thisembodiment be recorded on the disk 10 in a format different from that ofthe user data. If the correction data were recorded using the sameformat as that of the user data, the correction data could be easilyread, analyzed, copied, and distributed. In order to prevent thecorrection data-recorded disk 10 from being delivered to any willfulthird party, it is required that a recording format different fromtypical recording formats be used in recording the correction data tokeep anyone from accessing the correction data. The correction data mayalternatively be encrypted upon recording on the disk 10.

[0064] The correction data according to this embodiment can be embeddedas watermarks in the video and audio data corresponding to the userdata. For example, it may be effective to embed correction data forfixing trouble associated with a particular one of a plurality ofcontent objects, in the video and audio data of any of the contentobjects other than that particular content object as a watermark. Thistechnique permits such correction data to be read during the playing ofthe watermarked content object based on the watermark to correct theplaying program. This technique, which would make it harder for anyoneto locate correction data by embedding the correction data in user datawhich is large in size, is effective in protecting correction data.

[0065] The correction data according to this embodiment may be used todirectly record a corrected playing program, i.e., replacing an entireoriginal playing program with a corrected playing program, or recordonly difference data between an original playing program and a correctedplaying program. In the difference data approach, the corrected playingprogram needs to be generated using both the difference data indicatedby the correction data and the original playing program. The differencedata approach is more advantageous over the entire recording approach inreducing the size of the correction data.

[0066] Next, if it is determined that the reading and recording havebeen completed normally in step S26 (“YES” in step S27), a startposition address is changed (step S28). The start position address isgiven to indicate the head of a playing program corresponding to thecorresponding type of correction data, and recorded in a predeterminedarea of the first flash memory 19 or the second flash memory 20, forexample. Thus, by referring to the start position address changed instep S28, the start position for executing the playing program correctedby the corresponding type of correction data can be located.

[0067] Alternatively, a flag indicating that the recording has beenperformed normally may be appended to the start of the playing programcorresponding to the corresponding type of correction data, instead ofchanging the start position address in step S28. In this case, the flagshould be detected to locate the start position for executing thecorrected playing program.

[0068] Successively, if the playing program has been corrected normallyby the above process (“YES” in step S29), then the prohibition of thevarious operations in step S25 is cancelled (step S30), so that theoptical disk player will be ready to accept the operations such asturning off the power and giving user commands. Additionally, the diskID is stored in a memory within the CPU 15 so that the above correctingprocess will not be repeated on the disk 10 (step S31). In this way, theprocess of FIGS. 3 and 4 are brought to a normal end.

[0069] If, on the other hand, the reading and recording have not beencompleted normally in step S26 (“NO” in step S27), then the processbranches to the abnormal end routine. If the playing program has notbeen corrected normally (“NO” in step S29), the process resets the startposition address to the last address before the change in step S28 (stepS32), and then proceeds to the abnormal end routine.

[0070] When the process of FIGS. 3 and 4 have been terminated normally,the corrected playing program is recorded in the second RAM 18 and thesecond flash memory 20. From then on, the optical disk playercontinuously plays the disk 10 using the corrected playing programstored in the volatile second RAM 18. Furthermore, once the optical diskplayer is turned off, the user can load the corrected playing programresident in the nonvolatile second flash memory 20 using the ROM loader16 to play the disk 10. To further correct the corrected playing programunder this condition, another corresponding type of correction dataneeds to be recorded in the first flash memory 19 in step S26 since thepreviously used type of correction data is resident in the second flashmemory 20. That is, in the above process, every time the playing programis corrected, the latest corrected version of the playing program isstored alternately in the first flash memory 19 and the second flashmemory 20 to be resident therein.

[0071] It should also be appreciated that even if any abnormality, suchas sudden interruption of power during the reading of the correspondingtype of correction data in step S26, has occurred to cause failure innormal reading, this will create no problem in the next playback. Inthis case, the start position address will not be changed in step S28 sothat the disk 10 can be played normally using the original playingprogram recorded in one of the pair of RAM-flash memory systems.

[0072] Here, the location where the correction data is recorded on thedisk 10 according to this embodiment will be described. As mentionedabove, it is assumed in this embodiment that the correction data is tobe recorded in the lead out area or its outer region on the disk 10. Forexample, in a DVD format, the innermost and outermost radii of the leadout area following the user data area are specified, and the lead outarea can be identified by referring to a “last recorded address” whichis recorded in the lead in area.

[0073] Referring now to FIG. 6, a sector, which is a basic data unit ofa DVD, consists of an array of 172 bytes by 12 rows. Recorded at thehead of the sector are: sector information including a sector number, anarea type, a data type, and a layer number; a parity IED for detectingsector number error; and a flag reserved in the sector. The lead outarea is located by referring to the area type. At the tail of the sectorwhich follows the main data, a parity EDC for detecting error throughoutthe sector is appended.

[0074] It is specified that zeroes are to be written as main data insectors belonging to the lead out area. However, in this embodiment inwhich the correction data is to be recorded in the lead out area, a datapattern corresponding to the correction data is written, instead ofzeroes, in such sectors. There will be no trouble recording thecorrection data in the lead out area because the data written in thelead out area would never be referred to for any other purpose than forreading the correction data. It should be noted that the correction datawritten in the sectors belonging to the lead out area is identified byappending a predetermined header at the head of the lead out area, or,alternatively, the reserved flag mentioned above may be used for thesame purpose.

[0075] In another embodiment, the correction data may be recorded in apredetermined location in the outer region of the lead out area. In thisembodiment, a flag indicative of the correction data recording areaneeds to be appended, so that the correction data recording area can belocated by referring to that flag.

[0076] As mentioned above, the correction data may be recorded in thelead out area or its outer region on the disk 10 no matter how the leadout area is arranged, variable or fixed.

[0077] A modification of the above embodiment will be described as acase where the invention is applied to an informationrecording/reproducing apparatus. Specifically, an optical disk recorderas the information recording/reproducing apparatus performs recording ona recordable disk 10. In this case, correction data for correcting arecording/playing program executed by the optical disk recorder arerecorded on the disk 10. A basic flow of correcting process stepsperformed by the optical disk recorder is generally common to thatperformed by the optical disk player described above. As to therecordable disk 10, due to its being a blank disk, correction data to berecorded is relevant to trouble associated with the recording/playingprogram inherent in the optical disk recorder, not relevant to troubleassociated with a particular content object.

[0078] Various physical configurations may be conceivable to record suchcorrection data on the recordable disk 10. For example, in oneconfiguration, each of recording tracks alternates with each of wobblingguide tracks in the radial direction, to record user data on therecording tracks and extract a rotation reference signal from the guidetracks. In this configuration, the correction data is modulated alongthe guide tracks during the formation of the guide tracks, so that thecorrection data can be extracted during playback. This configurationprevents any willful third party from tampering the correction data onthe disk 10.

[0079] It should be noted that if the recordable disk 10 is a DVD, theoptical disk recorder uses a push-pull method for tracking, so that thecorrection data is extracted from push-pull signals. That is, thecorrection data on the recordable disk 10 can be read by a methoddifferent from a DPD method typically used by a DVD optical disk player,and hence enhanced security can be provided.

[0080] For a DVD-based disk 10 in which information pits are formed ingrooved tracks, correction data pits may be formed on land tracks to beread by the push-pull method. In this case also, the correction data canbe read by the method different from typical reading methods used byoptical disk players.

[0081] The following describes the case where the correction data isrecorded in the lead out area or its outer region on the disk 10 inadvance in an application of the invention to the optical disk recorder.In the recordable disk 10, a lead out area is defined when content datais recorded, and thus no lead out area has not yet been provided in anunrecorded disk 10. To record correction data on a disk in advance asmentioned above, one must keep in mind the following points.

[0082] That is, the correction data recording area may be set at apredetermined location in an area outward of the outermost location ofthe user data area, or a minimally required lead out area may be set ata predetermined location in an area outward of the outermost location ofthe user data area. The recording of the correction data should start atthe tail of content data recorded in the user data area, by which thelead out area can be defined with its start position defined. Since thelocation (address) of the correction data recording area or the lead outarea is identifiable beforehand as mentioned above, the optical diskrecorder does not need to specify the address every time it reads andrecords the correction data to correct its playing program.

[0083] As described in the foregoing, according to the invention, theinformation reproducing apparatus reads correction data recorded in thelead out area or its outer region and corrects the reproducing programusing the read correction data, when reproducing an informationrecording medium. Thus, upon occurrence of trouble in the reproducingprogram for reproducing the information recording medium, thereproducing program can be corrected quickly and properly based on aplurality of types of correction data corresponding to differentreproducing programs compatible with different models, etc. ofinformation reproducing apparatuses.

[0084] The entire disclosure of Japanese Patent Application No.2001-180695 filed on Jun. 14, 2001 including the specification, claims,drawings and summary is incorporated herein by reference in itsentirety.

What is claimed is:
 1. An information reproducing apparatus thatcorrects a reproducing program using correction data recorded on aninformation recording medium to reproduce record information recorded onthe information recording medium, the apparatus comprising: a correctioncontrol device for reading the correction data to be used to correct thereproducing program, from the information recording medium on which thecorrection data is recorded in a lead out area, to correct thereproducing program based on the read correction data; and areproduction control device for reproducing the record informationrecorded on the information recording medium according to a latestversion of the reproducing program which is corrected by the correctioncontrol device.
 2. An information reproducing apparatus that corrects areproducing program using correction data recorded on an informationrecording medium to reproduce record information recorded on theinformation recording medium, the apparatus comprising: a correctioncontrol device for reading the correction data to be used to correct thereproducing program, from the information recording medium on which thecorrection data is recorded in an area radially outward of a lead outarea, to correct the reproducing program based on the read correctiondata; and a reproduction control device for reproducing the recordinformation recorded on the information recording medium according to alatest version of the reproducing program which is corrected by thecorrection control device.
 3. The information reproducing apparatusaccording to claim 1, further comprising a nonvolatile storage devicefor storing the correction data, wherein the correction control devicerecords the correction data in a predetermined location of the storagedevice, and the reproduction control device executes a corrected versionof the reproducing program after confirmation that the correction datais recorded normally.
 4. The information reproducing apparatus accordingto claim 2, further comprising a nonvolatile storage device for storingthe correction data, wherein the correction control device records thecorrection data in a predetermined location of the storage device, andthe reproduction control device executes a corrected version of thereproducing program after confirmation that the correction data isrecorded normally.
 5. The information reproducing apparatus according toclaim 3, wherein the correction control device records a start positionof the correction data as a start position address, and the reproductioncontrol device executes the corrected version of the reproducing programby searching the start position address.
 6. The information reproducingapparatus according to claim 4, wherein the correction control devicerecords a start position of the correction data as a start positionaddress, and the reproduction control device executes the correctedversion of the reproducing program by searching the start positionaddress.
 7. The information reproducing apparatus according to claim 3,wherein while the correction data is recorded in the storage device, anoperation of turning off power is prohibited.
 8. The informationreproducing apparatus according to claim 4, wherein while the correctiondata is recorded in the storage device, an operation of turning offpower is prohibited.
 9. The information reproducing apparatus accordingto claim 1, wherein the correction data comprises difference databetween an original version of the reproducing program and a correctedversion of the reproducing program, and the correction control devicecorrects the reproducing program based on the original version of thereproducing program and the difference data.
 10. The informationreproducing apparatus according to claim 2, wherein the correction datacomprises difference data between an original version of the reproducingprogram and a corrected version of the reproducing program, and thecorrection control device corrects the reproducing program based on theoriginal version of the reproducing program and the difference data. 11.A method of correcting a reproducing program using correction datarecorded on an information recording medium, the method comprising: theprocess of reading the correction data to be used to correct thereproducing program, from the information recording medium on which thecorrection data is recorded in a lead out area; and the process ofcorrecting the reproducing program based on the read correction data.12. A method of correcting a reproducing program using correction datarecorded on an information recording medium, the method comprising: theprocess of reading correction data to be used to correct the reproducingprogram, from the information recording medium on which the correctiondata is recorded in an area radially outward of a lead out area; and theprocess of correcting the reproducing program based on the readcorrection data.
 13. The method of correcting a reproducing programaccording to claim 11, further comprising: the process of recording thecorrection data at a predetermined position of a nonvolatile storagedevice; and the process of recording a start position of the correctiondata as a start position address.
 14. The method of correcting areproducing program according to claim 12, further comprising: theprocess of recording the correction data at a predetermined position ofa nonvolatile storage device; and the process of recording a startposition of the correction data as a start position address.
 15. Themethod of correcting a reproducing program according to claim 11,wherein the correction data comprises difference data between anoriginal version of the reproducing program and a corrected version ofthe reproducing program, and the reproducing program is corrected basedon the original version of the reproducing program and the differencedata.
 16. The method of correcting a reproducing program according toclaim 12, wherein the correction data comprises difference data betweenan original version of the reproducing program and a corrected versionof the reproducing program, and the reproducing program is correctedbased on the original version of the reproducing program and thedifference data.
 17. An information recording medium on which recordedinformation as well as correction data for correcting a reproducingprogram executed by an information reproducing apparatus are recorded,wherein the correction data is recorded in a lead out area.
 18. Aninformation recording medium on which recorded information as well ascorrection data for correcting a reproducing program executed by aninformation reproducing apparatus are recorded, wherein the correctiondata is recorded in an area radially outward of a lead out area.
 19. Theinformation recording medium according to claim 17, wherein thecorrection data is recorded in a recording format different from arecording format in which the recorded information is recorded.
 20. Theinformation recording medium according to claim 18, wherein thecorrection data is recorded in a recording format different from arecording format in which the recorded information is recorded.
 21. Theinformation recording medium according to claim 17, wherein thecorrection data each comprises difference data between an originalversion of the reproducing program and a corrected version of thereproducing program.
 22. The information recording medium according toclaim 18, wherein the correction data each comprises difference databetween an original version of the reproducing program and a correctedversion of the reproducing program.